#include <iostream> #include <cstring> using namespace std; int main() { string str; cin >> str; int len = str.length(); for(int i = 0 ; i < len / 2 ; i++) { if( str[i] != str[len - 1 - i] ) { cout << "NO" << endl; return 0 ; } } cout << "YES" << endl; return 0; }